Multicarrier communication is a communication technique that utilizes a number of narrowband subcarriers to transmit information across a channel. Each subcarrier may be separately modulated with a data symbol before a composite signal including all of the modulated subcarriers is transmitted into the channel. One form of multicarrier communication that is growing in popularity is orthogonal frequency division multiplexing (OFDM). In an OFDM system, the subcarriers that are used to transmit information are each orthogonal to one another. A related form of multicarrier communication, known as orthogonal frequency division multiple access (OFDMA), also uses orthogonal subcarriers and, in addition, allows the subcarriers of transmitted signals to be allocated to different users in the system. OFDM, OFDMA, and other multicarrier techniques are being adopted by more and more wireless networking standards. There is a need for novel strategies for structuring communication activity in systems using these multicarrier technologies.